Frequencies for first 10,000 rows of paytype variable in nhamcsopd2004 dataset :

   expected source of |
              payment |      Freq.     Percent        Cum.
----------------------+-----------------------------------
                blank |         94        0.94        0.94
    private insurance |      2,776       27.76       28.70
             medicare |      1,582       15.82       44.52
             medicaid |      3,552       35.52       80.04
worker's compensation |        118        1.18       81.22
             self-pay |        870        8.70       89.92
            no charge |        311        3.11       93.03
                other |        334        3.34       96.37
              unknown |        363        3.63      100.00
----------------------+-----------------------------------
                Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016